Read/listen to/watch philosophy content. People wiser than us over the centuries have spent their lifetimes thinking about these questions. There's no single answer, but there are ways of thinking through this and coming to a place mentally that you can be happy with.

Personally I find Albert Camus's flavour of absurdism to be the best way I find things to make sense. The universe is irrational and meaningless, and that's great news. We carry on in a meaningless world and make our own meaning.

If you like podcasts then here are some great ones:

Happiness Lab

Hidden Brain

Overthink

Within Reason (although he's spending too much time in his analysis of religion, I prefer the other episodes)

Even just watching TV shows and movies helps, as long as you're paying attention to the story of the charachters, the messages and the experiences/motives of the characters. Seeing the stories of others (even if fictional) helps put your own situation in perspective.